The US military says its troops have killed 33 insurgents in a joint operation with Iraqi troops 80km (50 miles) north of Baghdad. It said several hundred US and Iraqi soldiers took part in the operation on Monday to reopen the water supply to the town of Khalis.

Residents say al-Qaeda fighters have a strong presence in the area.

Insurgents cut water supplies to Khalis several days ago by shovelling earth into an irrigation canal.

The US military said a joint assault force of US and Iraqi troops – which landed by helicopter – killed 13 insurgents. It said fire from attack aircraft killed 20 others.

It is not possible to deploy enough troops to protect all infrastructure when making it dysfunctional simply involves shovelling dirt into an irrigation canal (most likely a weir type of structure). There are too many kilometers of canals to protect. This isn’t to deny that there is a complex interplay between the availability of goods, services, security and government, and the population informing on insurgent identities and locations. Counterinsurgency remains a difficult venture.

But it is to say that when the impossible presents itself (i.e., protect all infrastructure, whether electrical grids, water supplies, or other utilities such as sewage, in order to win the population), the stipulations are unacceptable and the game must be reformulated. Coalition forces implemented the correct tactic to restore basic services.